At the beginning of Chapter 4, Sean Carroll describes the colobus monkey and its digestion. "Bacteria in the colobus's gut help to digest the large bolus of leaves as it travels slowly through his digestive system, and unique enzymes break down key nutrients that are released from the bacteria". What type of symbiotic relationship is this? Why?
In addition, identify and explain each type of symbiotic relationship, with an example for each. For each example, explain how the relationship is selectively advantageous for at least one organism involved.
Well, the relationship you describe is a mutualistic one, because the bacteria help the monkey digest the food, and the bacteria benefit by being provided with a niche and a food supply in the gut.
ReplyDeleteTapeworms that reside in human stomachs sap nutritive macromolecules away from the organism, and so this relationship is parasitic (the tapeworms benefit and the humans are harmed by the possible malnutrition).
A commensalist relationship exists between barnacles and whales, whereby the whales are neither helped nor harmed by the self-adhered barnacles that use the whale as a niche and moving object that creates a current through which the barnacles obtain food.
The relationship between the colobus monkey and the bacteria in its gut is mutualistic, meaning both participants benefit from the relationship. The bacteria get a relatively safe place to live and receive nutrition from the food the monkey ingests. In turn, the monkey receives the benefit of increased digestive capabilities, as the bacteria releases enzymes the monkey cannot produce on its own.
ReplyDeleteParasitism = one organism benefits, the other is harmed
EX: Ticks are parasites to humans. Ticks feed on blood from humans and other animals; the host is harmed by the loss of blood, and can also sometimes contract a disease (often Lyme Disease) from the tick.
Commensalism = One organism benefits, the other is left unaffected
EX: Vultures are in a commensalistic relationship with lions and other predators, vultures benefitting and the predators being unaffected. After a predator kills and feasts upon its prey, a considerable portion of meat is left on the carcass. The vultures then feed on this meat left unwanted by the predator.
Mutualism = both organisms benefit
EX (in addition to the colobus monkey): Mycrorrhizal association between a plant and a fungus; the fungus colonizes the roots of a plant, giving the fungus access to the carbohydrates produced by the plant, and the plant gains absorptative capabilities with the increased surface area of the fungal roots and the more specialized absorptative abilities of the fungus.
As Sam and Eric pointed out, the relationship you described between the colobus monkey and the bacteria living in the monkey's gut is a mutualistic relationship, because both organisms benefit. The bacteria get a living space and a food supply, while the colobus monkey benefits by utilizing the bacteria to help digest the bolus of leaves. There are three types of symbiotic relationships.
ReplyDeleteA Mutualistsic symbiotic relationship is one in which both organisms benefit from the interaction, like the colobus monkey and the bacteria. An example of a mutualistic relationship is that between the oxpecker bird and the zebra. The oxpecker lands on the zebra and eats the ticks that live on the zebra's skin. The oxpecker gets a food supply, and the zebra reduces the threat from parasites.
A Commensalist symbiotic relationship is one where one organism benefits, and the other organism is unaffected, neither benefitting or being harmed. An example of a commensalist relationship is that of the monarch butterfly and the viceroy. The monarch butterfly tastes bad to predators, but the viceroy does not. The viceroy attempts to mimic the monarch so that predators, thinking the viceroy is a distasteful monarch, will avoid it. This relationship helps the viceroy, because the viceroy gets protection from predators, but the monarch butterfly is unaffected, since the predators already avoid the monarch.
Finally, a parasitic relationship is a relationship in which one organism benefits, but the other organism is harmed from the relationship. An example of a parasitic relationship would be mosquitos, such as Anopheles gambiae (italicize), preying on human blood. The mosquito benefits from the food supply in the blood, while the human is harmed by the loss of blood and occasionally by pathogens that enter into the human blood, either from the opening made by the mosquito or from the mosquito itself, such as malaria.